"Des citrons verts" are not necessary limes, they can just be unripe (regular) lemons.
I replied "You buy green lemons." was it was correct when I just answered it, it may have been added since you wrote this.
I answered "You are buying green limes". Why is this not correct if citrons can be lemons or limes?
There is no need of the word verts.citrons verts should have been green lemons isn't it?
The correct answer is ' You buy limes' but that sentence in French means ' You buy green limes '??
Duolingo you had "citrons verts" in earlier parts and I put limes and you marked it wrong. Frustrating